Commas
Use the Oxford comma in lists of three or more items in a sentence.
Use commas to separate clauses. Break up longer or difficult-to-read sentences into shorter chunks.
Dependent clauses that start a sentence, end with a comma. (Learn more)
Example: After you open the file, save it to your desktop with a different name.
Oxford comma
Use the Oxford comma. The Oxford comma should break up lists of three or more items in a sentence.
Example: Stream for Free, Pro, and Business plans
Without the Oxford comma, readers might misunderstand this header as free streaming for Pro and Business plans.